HIGH SALIENCE / GLOSSARY

REFERENCE · SEPTEMBER 26, 2026

AI Search Glossary

Plain definitions of the terms used in AI search and AI SEO, from AEO and GEO to query fan-out and recommendation share. Each entry is short on purpose and links to a fuller guide where one exists.

BY BIKE HAWLEY, FOUNDER · UPDATED

AEO (answer engine optimization)

AEO (answer engine optimization) is the practice of optimizing content and brand presence so you are used as the answer in featured snippets, voice responses and AI-generated answers. See AEO vs SEO and our AEO service.

Agentic Commerce Protocol (ACP)

The Agentic Commerce Protocol (ACP) is an open standard from OpenAI, built with Stripe and launched in September 2025, for connecting merchants to ChatGPT. In March 2026 OpenAI extended it to product discovery. See ChatGPT shopping.

Agentic search is search in which AI systems carry out several steps for a user, such as searching, comparing options and opening pages, instead of returning a single answer. Still early, and not yet something anyone can measure reliably for brand visibility.

AI citation

An AI citation is a source an AI answer links to or names as its evidence. Citations are the one part of how an answer is built that you can observe from the outside. See AI citations.

AI Mode

AI Mode is Google's conversational search experience, which breaks a question into many searches (query fan-out) and writes one answer with links.

AI Overviews

AI Overviews are the AI-written summaries Google shows at the top of some search results, with links to sources. Google says they rely on its core ranking systems.

AI SEO

AI SEO is the umbrella term for optimizing across Google and AI search as one program. See AI SEO.

AI visibility

AI visibility is how often and how favorably a brand appears in AI answers to relevant questions. Best reported as presence, recommendation share and citation share. See AI visibility.

AIO

AIO is an ambiguous abbreviation. Some use it for AI optimization in general, others for Google's AI Overviews. Ask which is meant.

Alternatives query

An alternatives query is a buyer question such as "X alternatives" or "cheaper alternative to X". The answers show which brands an AI system treats as substitutes for X. Our brand pages report what ChatGPT suggests instead of each brand.

Anchor mention

In our research codebook, an anchor mention is a brand named in the question itself, such as HubSpot in "HubSpot alternatives". It is counted separately so the question does not inflate the brand's numbers.

Answer engine

An answer engine is any system that responds with an answer rather than a list of links: AI chat products, AI search features and voice assistants.

Asynchronous AI Overview

An asynchronous AI Overview is an AI Overview that loads after the rest of the results page. Tracking tools that do not wait for it record the Overview as missing or empty; in our four-industry snapshot, 37 of 94 Overviews loaded this way.

Bingbot

Bingbot is Microsoft's search crawler. Bing's index is what Microsoft Copilot's web answers are grounded in, so a site Bing cannot crawl is hard for Copilot to cite.

Brand mention

A brand mention is any appearance of a brand's name on a page or in an answer, with or without a link. See brand mentions.

Brand salience

Brand salience is a marketing-science term for how easily a brand comes to mind in buying situations, associated with the Ehrenberg-Bass Institute. It is the idea underneath Category Salience. See brand salience.

Category entry points

Category entry points are the buying situations, needs and cues that bring someone into a category, a term from the Ehrenberg-Bass Institute's work on mental availability. A brand linked to more of them comes to mind more often. See category entry points.

Category Salience

Category salience, as defined by High Salience, an AI search and SEO agency, is how consistently a brand is found, cited and recommended across the search results, AI answers and third-party sources that shape a buying category.

ChatGPT ads

ChatGPT ads are sponsored placements OpenAI shows below ChatGPT answers for users on the Free and Go plans, tested from February 2026. OpenAI says advertisers cannot change the answers. See ChatGPT ads.

ChatGPT search is the web search mode in ChatGPT, launched in October 2024, which answers with live sources and citations. OpenAI says sites that want to appear in it should allow OAI-SearchBot.

ChatGPT shopping

ChatGPT shopping is the set of product results ChatGPT shows when someone asks what to buy. OpenAI says they are selected independently and are not ads.

ChatGPT-User

ChatGPT-User is OpenAI's agent for fetching a page when a ChatGPT user asks for it. It is user-initiated rather than automatic crawling.

Chunking

Chunking means splitting text into small passages so a retrieval system can match them to a question. Retrieval systems do this themselves; Google says sites do not need to restructure content into chunks for its AI features.

Citation share

Citation share is how often your own pages appear among the sources AI answers cite, for a defined set of questions.

Claude-SearchBot

Claude-SearchBot is Anthropic's crawler for improving Claude's search results. Allow it if you want to appear in Claude search answers.

ClaudeBot

ClaudeBot is Anthropic's crawler for collecting model training data. Blocking it is a training decision, separate from search visibility.

Co-occurrence

Co-occurrence means two brands appearing in the same answer or on the same page. In AI answers, the brands that co-occur most often with yours are the competitive set the model has built for you, which is not always the one you would choose.

Comparison query

A comparison query is a head-to-head buyer question such as "Pipedrive vs HubSpot". In our teardowns ChatGPT usually recommends both options for different buyers rather than naming a winner. Comparison questions help decide a software shortlist, so B2B SaaS SEO services treat them as core targets.

Context window

A context window is the amount of text a language model can take into account at once, including the question, any retrieved pages and its own answer so far.

Conversational search is searching by asking questions in natural language, with follow-ups that keep the earlier context, as in ChatGPT, Perplexity and Google AI Mode.

Copilot

Copilot is Microsoft's AI assistant. Its answers about the web are grounded in Bing search results.

Crawler

A crawler is software that fetches web pages for a search engine or AI company, such as Googlebot or OAI-SearchBot. robots.txt tells crawlers what they may fetch. See AI crawlers.

Deep Search is a more intensive mode of Google's AI Mode, launched for paying subscribers in July 2025, that runs many more searches before writing a report.

Digital PR

Digital PR is earning coverage and mentions on news, trade and review sites. For AI search its value is that those sites are among the sources models read when they describe a category. See source authority.

E-E-A-T

E-E-A-T stands for experience, expertise, authoritativeness and trustworthiness: the framework Google's human quality raters use to judge pages. The first E, for experience, was added in December 2022. It is a guideline for raters, not a single ranking score. See E-E-A-T.

Embedding

An embedding is a list of numbers that represents the meaning of a piece of text, so that passages with similar meaning sit close together. Embeddings are how many retrieval systems find passages that match a question.

Entity

An entity is a distinct thing a search system recognizes, such as a company, product or person, with attributes and relationships. Consistent entity information helps systems describe you correctly. See semantic SEO.

Entity salience

Entity salience is a natural language processing score for how central an entity is to a document. Version 1 of Google's Cloud Natural Language API reports it on a scale from 0 to 1; version 2 dropped the field. See entity salience.

A featured snippet is the boxed answer Google shows above regular results for some questions. The original target of AEO.

Gemini

Gemini is Google's family of AI models and the name of its AI assistant app.

Generative AI

Generative AI means AI systems that produce new text, images or other content in response to a prompt, rather than only classifying or retrieving existing content.

Generative AI performance report

The Generative AI performance report is a Search Console report, open to all sites since August 31, 2026, that shows impressions in AI Overviews and AI Mode by page, country, device and date. It does not show clicks. See AI Overviews tracking.

GEO (generative engine optimization)

GEO, generative engine optimization, is the work of improving how often and how favorably a brand appears in answers written by generative AI systems. Named in a 2023 research paper. See GEO vs SEO and our GEO service.

Google Business Profile

Google Business Profile is Google's free listing for local businesses, shown in Maps and local results. Google says local ranking depends mainly on relevance, distance and prominence.

Google-Extended

Google-Extended is a robots.txt control that governs whether content is used for Google's Gemini models. It does not affect inclusion or ranking in Google Search.

Googlebot

Googlebot is Google's search crawler. It covers Google Search, including AI Overviews and AI Mode, so blocking it removes a site from all of them.

GPTBot

GPTBot is OpenAI's crawler for model training. Blocking it does not remove a site from ChatGPT search, which uses OAI-SearchBot.

Grounding

Grounding means tying an AI answer to retrieved sources rather than to the model's training data alone, which is what makes citations possible.

Hallucination

A hallucination is an AI answer that states something false with confidence, such as a wrong price or a feature a product does not have.

Head-to-head query

A head-to-head query is a question comparing named options, such as "Gusto vs ADP". In our research, an answer can pick one side, recommend both, or decline to pick.

Indexing

Indexing is Google storing a page so it can appear in results. A page must be indexed, and eligible to show a snippet, to appear in AI Overviews or AI Mode.

Instant Checkout

Instant Checkout is ChatGPT's in-chat purchase feature, launched in September 2025 and scaled back in March 2026, when OpenAI moved shoppers to merchants' own checkout by default.

Knowledge cutoff

A knowledge cutoff is the date after which a model's training data ends. Anything newer can only reach an answer through retrieval, which is why AI search products fetch live pages.

Knowledge Graph

The Knowledge Graph is Google's database of entities and the facts connecting them, introduced in 2012. It powers knowledge panels and helps Google recognize what a page is about.

Knowledge panel

A knowledge panel is the information box Google shows for a recognized entity, such as a company or person, drawn from its Knowledge Graph. See knowledge panels.

Large language model (LLM)

A large language model (LLM) is a model trained on large amounts of text to predict and generate language. ChatGPT, Claude, Gemini and the models behind Perplexity are all built on LLMs.

Listed mention

In our research codebook, a listed mention is a brand an AI answer names as an option without assigning it to any case or fit.

Listicle

A listicle is a "best X" list article. Listicles dominate Google's results for many commercial questions and are among the pages AI answers cite, which is why being included in the right ones matters.

LLMO (large language model optimization)

LLMO, large language model optimization, is another name for the same work as GEO and AEO, framed around language models, including how they describe a brand unprompted. See LLM SEO.

llms.txt

llms.txt is a proposed markdown file listing a site's key pages for AI tools. Google Search ignores it, and server logs show major AI crawlers rarely request it. See llms.txt.

Local pack

The local pack is the block of map results Google shows for searches with local intent, drawn from Google Business Profiles.

Merchant Center

Merchant Center is Google's tool for submitting product data. Products in it can appear in free listings across Search, the Shopping tab, Images, Lens, YouTube and Gemini.

Merchant listing markup

Merchant listing markup is product structured data for pages where people can buy. It makes pages eligible for Google's shopping experiences. Review pages use product snippet markup instead.

No-pick answer

A no-pick answer is an AI answer that makes no pick of its own, often because it asks for more context first. Payment processing had the most in our teardowns: 22 of 100 answers.

OAI-SearchBot

OAI-SearchBot is OpenAI's search crawler. OpenAI recommends allowing it in robots.txt for sites that want to appear in ChatGPT search.

Organization schema

Organization schema is structured data that describes a company: name, logo, contact details and links to official profiles through sameAs. Google says it can influence the logo shown in results and knowledge panels.

Passage ranking

Passage ranking is Google's ability to rank a page for a specific passage within it, launched in 2021. Useful context for AI search, since answers are assembled from passages, not whole pages.

People Also Ask

People Also Ask is the box of related questions Google shows in many results, each expanding to a short answer and a source. A good map of the questions buyers ask next.

People-first content

People-first content is Google's term for content made to help people rather than to rank, described in its guidance on helpful, reliable content.

Perplexity

Perplexity is an AI search engine that answers questions with numbered citations to live web sources.

Perplexity-User

Perplexity-User is Perplexity's agent for fetching a page when a user asks. Perplexity treats it as a user request, so it generally does not follow robots.txt.

PerplexityBot

PerplexityBot is Perplexity's search crawler, which surfaces and links sites in Perplexity answers. Perplexity says it is not used to train foundation models.

Picked mention

In our research codebook (v2.0), a picked mention is a brand the AI answer itself chooses as its verdict, overall or for a case: "my pick", "choose X if", a shortlist it tells you to act on, or the direct answer to "which should I use". Across 21 teardowns, 79 percent of brand appearances were picks.

Presence

Presence is the share of relevant AI answers that name your brand at all, whether or not they recommend it.

Prompt tracking

Prompt tracking means running a fixed set of questions through AI systems on a schedule and recording which brands and sources appear. Answers vary between runs, so results should be read as frequencies over many questions, not as fixed positions.

Query fan-out

Query fan-out means splitting one question into many searches, then combining the results into one answer. Google says both AI Mode and AI Overviews may use it. See query fan-out.

RAG (retrieval-augmented generation)

RAG, retrieval-augmented generation, is the pattern most AI search products follow: retrieve relevant documents first, then generate an answer from them.

Recommendation share

Recommendation share is the share of the AI answers naming a brand that also choose it. We report two levels: recommended (assigned to a stated case) and picked (the answer's own verdict). The pick share is the one closest to a buying decision.

In our research codebook (v2.0), a recommended mention is a brand an AI answer assigns to a stated case or fit, such as "best for small teams". It includes picked brands. See the teardowns for how often each brand gets there.

Retrieval

Retrieval is the step where an AI search system fetches pages or passages relevant to a question before writing its answer. What gets retrieved sets the limits of what the answer can say.

robots.txt

robots.txt is a plain text file at the root of a site that tells crawlers which paths they may fetch. It is how sites allow or block specific AI crawlers.

sameAs

sameAs is a schema.org property that links an entity on your site to its profiles elsewhere, such as LinkedIn or Wikipedia, so systems can connect them as the same company or person.

Scaled content abuse

Scaled content abuse is a Google spam policy, added in March 2024, against producing many pages mainly to manipulate rankings, whether the pages are written by software, people or both.

Search Generative Experience (SGE)

Search Generative Experience (SGE) was Google's 2023 Search Labs experiment with AI-written answers. It became AI Overviews when Google launched them in the United States in May 2024.

Search intent

Search intent is what a person wants from a query: information, a specific site, a comparison or a purchase. AI answers and Google results both change shape with intent.

Search profile

A search profile is a US-only Google feature introduced in 2026 for people with large followings on YouTube, Instagram, X or TikTok. Google says creating one does not directly affect ranking.

Search Quality Rater Guidelines

The Search Quality Rater Guidelines are the handbook Google gives the people it pays to evaluate search results. Their ratings help Google test its systems but do not change rankings directly. The current version is dated September 11, 2025.

Semantic search is search that matches meaning rather than exact words, so a question can find a passage that answers it without sharing its phrasing.

SERP

SERP stands for search engine results page: everything Google or another engine shows for a query, including organic results, ads, AI Overviews and other features.

Share of voice

Share of voice is a brand's share of all brand mentions across a defined set of questions, compared with its competitors. In AI search it is usually measured as presence and recommendation share. See AI share of voice.

Shopping Graph

The Shopping Graph is Google's dataset of products, sellers, prices and reviews, which powers shopping results and shopping in AI Mode.

Snippet controls

Snippet controls are directives such as nosnippet, data-nosnippet and max-snippet that limit how much of a page Google can show. They limit use in AI Overviews and AI Mode as well as in normal results.

Source authority

Source authority is how much weight search and AI systems give a site as evidence on a topic. In practice, whether the pages that shape answers in your category describe you.

A sponsored agent is an ad format OpenAI is testing in closed alpha in 2026 that lets a user chat with a business's own AI from a ChatGPT ad.

Structured data

Structured data is machine-readable markup, usually schema.org, that describes a page. Useful for rich results and clarity; Google says no special markup is needed for its AI features.

Topical authority

Topical authority is the idea that a site covering a subject thoroughly is treated as a more reliable source on it. Google has described a topic authority system for news; in wider SEO use the term is looser and has no published metric.

Universal Commerce Protocol (UCP)

The Universal Commerce Protocol (UCP) is a protocol Google launched in January 2026 with partners including Shopify, Etsy, Wayfair, Target and Walmart, used for checkout in AI Mode and the Gemini app.

Unlinked mention

An unlinked mention is a reference to a brand on another site that does not link to it. Google has not published a rule that counts it as a ranking signal.

Vector search means finding the passages whose embeddings are closest to the embedding of a question. It is one of the main retrieval methods behind AI search.

Voice search means asking a question aloud to an assistant. Voice answers usually give a single result, which made them an early target of answer engine optimization.

YMYL (Your Money or Your Life)

YMYL, short for Your Money or Your Life, covers topics that could significantly affect people's health, financial stability, safety or society. Google's rater guidelines hold them to the highest standard of trust and name health or safety, financial security, and government, civics and society among them.

A zero-click search is a search that ends without a click to any website, because the answer was on the results page or in the AI response. See zero-click search.

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